Re: Issue in postgres_fdw causing unnecessary wait for cancel request reply - Mailing list pgsql-hackers

From Kuwamura Masaki
Subject Re: Issue in postgres_fdw causing unnecessary wait for cancel request reply
Date
Msg-id CAMyC8qrjv2=oSV6bNC6TWbb01SyW1Se7Lyy7gZFfpVH5bCB6-w@mail.gmail.com
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In response to Re: Issue in postgres_fdw causing unnecessary wait for cancel request reply  (Fujii Masao <masao.fujii@oss.nttdata.com>)
List pgsql-hackers
Hi, Fujii-san

> Regarding the WARNING message, another idea is to pass the return value
> of PQgetCancel() directly to PQcancel() as follows. If NULL is passed,
> PQcancel() will detect it and set the proper error message to errbuf.
> Then the warning message "WARNING:  could not send cancel request:
> PQcancel() -- no cancel object supplied" is output.

I agree to go with this.

With this approach, the information behind the error (e.g., "out of memory") will disappear, I guess.
I think we have to deal with it eventually. (I'm sorry, I don't have a good idea right now)
However, the original issue is unnecessary waiting, and this should be fixed soon.
So it is better to fix the problem this way and discuss retaining information in another patch IMO.

I'm afraid I'm new to reviewing.
If I'm misunderstanding something, please let me know.

Masaki Kuwamura

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